Envelope-to: dave@picks.force9.co.uk Delivery-date: Thu, 22 Sep 2005 21:13:55 +0100 Received: by ptb-mxcore02.plus.net with spam-scanned (PlusNet MXCore v2.00) id 1EIXS4-00015L-EE for dave@picks.force9.co.uk; Thu, 22 Sep 2005 21:13:54 +0100 Received: from post.thorcom.com ([193.82.116.20]) by ptb-mxcore02.plus.net with esmtp (PlusNet MXCore v2.00) id 1EIXS4-00014T-9w for dave@picks.force9.co.uk; Thu, 22 Sep 2005 21:13:52 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1EIXQO-0001nO-0F for rs_out_1@blacksheep.org; Thu, 22 Sep 2005 21:12:08 +0100 Received: from [193.82.59.130] (helo=relay2.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1EIXQN-0001nF-B6 for rsgb_lf_group@blacksheep.org; Thu, 22 Sep 2005 21:12:07 +0100 Received: from smtp808.mail.ukl.yahoo.com ([217.12.12.198]) by relay2.thorcom.net with smtp (Exim 4.51) id 1EIY9q-0007UP-4p for rsgb_lf_group@blacksheep.org; Thu, 22 Sep 2005 21:59:08 +0100 Received: (qmail 64091 invoked from network); 22 Sep 2005 20:11:57 -0000 Received: from unknown (HELO aquarids) (ganymede444@86.132.155.220 with login) by smtp808.mail.ukl.yahoo.com with SMTP; 22 Sep 2005 20:11:57 -0000 From: "Dave G3WCB" To: rsgb_lf_group@blacksheep.org Date: Thu, 22 Sep 2005 21:12:23 +0100 Message-ID: MIME-Version: 1.0 X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2911.0) X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1441 Importance: Normal In-Reply-To: Subject: LF: RE: DFCW Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-PN-SpamFiltered: by PlusNet MXCore (v2.00) Hi, Chris. I use the program "QRS v4.02" from ON7YD to send both QRSS amd DFCW. It's very easy to use and configure, and you can do useful things like alter the inter-character spacings, flip DFCW mark and space, etc. You need to build a 1-transistor interface/level shifter to key the transmitter, but the circuit is contained in the "Help" documentation that comes with the program. http://www.qsl.net/on7yd/software_main.htm If you can't get enough swing with a vari-cap, you can use a 1N918 or 1N4148 Si diode as a switch, and use it to switch a trimmer capacitor across the crystal. I use a crystal in the 3MHz range in a Colpitts configuration, and the DFCW control signal switches a 3-30 pF trimmer across the crystal. For DFCW3 speeds, about 3 or 4 Hz shift is all you need. If you go to DFCW10 or longer, you need only about 1 Hz or less shift. The convention seems to be that the dash is the higher frequency. 73 Dave G3WCB IO1RM -----Original Message----- From: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blacksheep.org]On Behalf Of OSBORN, Chris Sent: 22 September 2005 13:57 To: LF Group (E-mail) Subject: LF: DFCW My new LF TX is nearly finished and I would like to add the option of DFCW. I was thinking of just placing a varicap diode in parallel with the crystal and thus pulling the frequency for achieving the dots / dashes. Can someone direct me to a circuit diagram and software to achieve this ? 73 Chris G3XIZ